The Best Ultralight Sleeping Bags of 2017

Are you in the market for a new sleeping bag but want only the lightest one money can buy? We meticulously researched over 50 of the best ultra-light contenders available and selected the best 12 to put to the test. Over the course of spring, summer, and fall, our team of expert reviewers spent hundreds of nights sleeping in these bags while trekking through the Himalaya in Nepal, exploring the deep canyons of the Utah desert, and enjoying the pristine wilderness in the Rockies of Wyoming and Colorado. Through these trials and adventures, we have learned which light down bags were the most comfortable, the warmest, packed down the smallest, and are the most versatile — information we happily share with you here. Whether you are a thru-hiker, an alpinist, an aspiring backpacker, or merely believe that "light is right," this comparative review will help you find the best ultra-light sleeping bag for your needs.

Analysis and Award Winners

Review by:
Andy WellmanSenior Review EditorOutdoorGearLab

Last Updated:
Tuesday
October 24, 2017

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Updated October 2017
In addition to our overhaul in the spring, we've perused the market and discovered the Marmot Phase 30, which took home our Top Pick for Water Resistance. Testing across Colorado, Wyoming, Utah, and Nepal, our expert testers pushed these bags to their limits, discovering that the Feathered Friends Flicker 40 remains our Editors' Choice winner. We've also included the new Patagonia 850, which wins a Top Pick as a Mummy Bag.

Due in large part to its incredible versatility, the Feathered Friends Flicker 40 UL was the highest rated bag in our review. Whether you are trying to ventilate on a hot night or bundle up to stay warm when the temperature drops, this bag has you covered. The full-length zipper that allows this bag to be both a hoodless mummy and a flat quilt, as well as a myriad of options in between, was unrivaled amongst the other contenders we tested for this review. We also loved how the Flicker 40 UL paired super high loft 950+ fill quality down with a shell made of natural water resistant and breathable Pertex Endurance UL, sparing no expense to make sure that only the very best and lightest materials were used. Dual draw cords at both the head and feet made this bag an excellent choice for wearing around on chilly mornings, and the already mentioned full-length zipper was far higher quality and more functional than the weight saving buckle or strap systems used on some competing quilts. For this review, we opted to purchase the 40F version to test the lightest Flicker available, but those wanting a little extra warmth at only a tiny cost in weight can also shop 30F or 20F versions. As the clear winner of our comparative review, we happily recommend you begin your search for an ultra-light sleeping bag right here.

Best Bang for the Buck

Enlightened Equipment Revelation 20

While not quite as high scoring as our Editors' Choice winning Feathered Friends Flicker 40 UL, the Enlightened Equipment Revelation 20 comes at a significantly lower price of $270. If the price is your central consideration, it is hard to find an ultralight sleeping bag that offers anywhere near as much versatility or warmth as this bag, without overly burdening the budget. Enlightened Equipment provides perhaps the most highly customizable sleeping bag you could ask for, which is fantastic for people with who are extra tall or wide, want more or less insulation, or are very particular about what colors they want. For this review, we chose this non-customized "off the shelf" model, which ships immediately upon order instead of waiting for a custom bag to be constructed. As a highly versatile quilt that is also very warm, this bag easily ranked in the top half of the products we tested, at an entirely reasonable price.

The Best Ultralight Mummy Bag

Patagonia 850 Down 30

As the third highest rated ultralight sleeping bag we tested, the Patagonia 850 Down 30 deserves recognition as the best fully enclosed hooded mummy bag. While quilts may offer greater versatility or options for venting, when it comes to hunkering down outside on a cold night, nothing beats the tight wrap and over-the-head protection of a hooded mummy bag. As one of Patagonia's first generation of sleeping bags, we are pleasantly surprised that they managed to create such an excellent product on their first try — hats off! While it is on the heavier side compared to the competition, it was also among the warmest bags we slept in, despite only coming with a 30F rating. Its well designed and functional features, such as a two-way zipper, hidden cord-lock release buckles, and more spacious foot box, easily endeared it to the hearts of all who tried it. If you want light, warm, and love the snuggly cocoon of a mummy bag, this is an ideal option for you.

Top Pick for Water Resistance

Marmot Phase 30

Combination of Pertex fabric and Down Defender treated insulation makes it supremely water resistant

Very lightweight for a fully hooded mummy bag

Full-length zipper allows easier ventilation than most mummy bags

Not nearly as warm as its rating suggests

Zipper has an annoying habit of snagging on draft tube fabric

Looking to go ultra-light, but still worried about using a down-filled sleeping bag every night in a wet climate? Then we recommend you check out the Marmot Phase 30, our Top Pick for Water Resistance due to its winning combination of Pertex Quantum shell fabric and Marmot's proprietary Down Defender DWR treatment for the 850 fill power down. Down offers far and away the best warmth-to-weight ratio of any insulation, which is why we have chosen only down filled bags for this ultra-light review. But where down has historically failed is in wet climates; if it gets wet, it loses 90% of its loft, as well as its heat-trapping properties. For this reason, outdoor enthusiasts have long been discouraged from trusting down in wet climates, and with good reason. To remedy this problem, most companies, including Marmot, have developed "hydrophobic down," which is essentially down that has been treated with a DWR (durable water resistant) coating. Marmot claims that their Down Defender treatment allows their down to stay drier longer, maintain more loft, and dry out quicker than untreated down. While we couldn't verify their exact percentages, our anecdotal testing proved to us that this technology works. Combined with the capillary wicking and natural water-resistant Pertex Quantum 10d fabric on both the inside and outside, the Phase 30 offers up a formidable barrier against soaking rains. If you commonly backpack in the Northern Cascades or have a long-ingrained fear of combining wet weather and down insulation, then this could be the perfect ultralight bag for you.

Top Pick for Extreme Packability

Sea to Summit Spark I

Packs down to the size of a softball (!) in the included compression stuff sack

Low price

Only suitable for warm summer use

Minimal down loft

For certain activities like self-supported bike touring, bike packing, fast-packing, or adventure racing, weight and size are simply the most important characteristics of any, and every, piece of gear. That's why we couldn't help but recognize the Sea to Summit Spark I as the lightest and smallest down sleeping bag we have ever seen! At a measly 12.7 ounces, this thing weighs less than a jacket, and stuffs into an included compression sack the size of a softball! Of course, a sleeping bag so small and light comes with obvious drawbacks, such as a comfort rating of 54F, ensuring it can only be used during the warmest summer nights (or by those willing to suffer a little bit for its attributes). Regardless, for late spring backpacking in the canyon country of the Utah desert, it was more than enough to keep us comfortable. If you want a summer bag at a reasonable price that packs so small it's almost a joke, check out this sleeping bag.

Notable for Those on a Tight Budget

Kelty Cosmic Down 40

Most ultralight backpackers will scoff at the Comic Down 40. We did as well until we used it. While it would score low in almost every metric in this review, we found it still works. As long as we wore enough clothes (hat, thermals, a down jacket) we stayed warm in temps down to 30 degrees in the High Sierra above 11,000 feet. We list it here for people that are on a very tight budget, or only backpack once a year, and want something that costs $120 or less. The expensive gear in the review is often high-quality and worth it if you backpack a lot. But if you're just getting into traveling fast and light, we don't think money should keep you from diving in. Products like the Cosmic Down 40 fit that need.

We wouldn’t recommend this quilt for pretty much any reason, and think it needs to be sent back to the design lab.

Analysis and Test Results

Over the course of four spring months in 2017, we put each of these 12 ultralight mummy bags and quilts to the test in a wide variety of conditions with the aim of deciding what is the best ultralight sleeping bag for you. We rated each bag on a scale of one to ten for five separate metrics: warmth, weight, comfort, versatility, and features. Each metric was then weighted according to the relative importance that we deemed it had in overall performance, and each product ended with a cumulative score between 1-100. In all cases, we assigned scores based on comparisons between the products, so the highest scoring sleeping bag for a given metric was the best compared to the rest, and the lowest score was less effective compared to the competition.

A magnificent campsite, and a great place to test out the best ultralight sleeping bags and quilts. This is near the small village of Samdo on the Manaslu Circuit in Nepal, using the Palisade 30 and The North Face Superlight 15.

Below we discuss each rating metric in depth, delving into the nuances of what it means to a bag's overall performance, how we tested for that parameter, the relative weight of its score, and finally which products were the most and least useful for each metric. Over our extensive testing period, we learned that ultralight sleeping bags have some serious advantages over regular Backpacking Sleeping Bags, but often suffer from some serious disadvantages as well. For this reason, we recommend that you thoroughly research and understand a product's relative merits and weaknesses by checking out their product pages before making a purchase. For more information, you can also check out our Buying Advice Article, which goes into much greater detail about ultralight sleeping bag features, materials, and the buying process.

Hanging out to watch the sunset and eat dinner in the award winning Feathered Friends Flicker 40, on an overnight trip into the Uncompahgre Wilderness in Colorado.

Warmth

Getting a good night's sleep is key to enjoying your overnight outdoor adventures, and warmth plays a critical role in making that happen. More importantly, though, warmth is important for your safety. In the quest to lighten your load for comfort and speed, compromising on warmth is just not an option. If your ultralight sleeping bag, paired with your warm clothing, does not keep you warm enough to sleep well and recuperate from your big day of hiking, climbing, or bike riding, well, it doesn't matter how little it weighs. Fortunately, the innovative bags we test here deliver excellent warmth-to-weight ratios. We strongly believe that you should choose your warmth based on the weather you will encounter, and our warmth ratings contribute 30% to each product's overall score.

The amount of loft, or the heat-trapping space created around you by the down fill of your bag, is the primary determining factor of how warm a sleeping bag will be. To build loft while adding the least amount of weight, the majority of these bags use very high quality down with high fill powers. Secondary to the loft is construction. To prevent the down from moving around inside the bag, manufacturers sew in baffle patterns that create little chambers to trap the down in place and prevent it from moving about. The type of baffles (sewn-through vs. box baffle) impacts how many thin spots where very little or even no down protects you from the chill outside. Additionally, the shape of the baffles is different on every bag, and some are more effective than others at preventing "dead spots" and keeping the down in place.

The Revelation 20 is the warmest one that we tested, and on a warm summer night, there was no need to fasten it up underneath us. Going light, Peter didn't even bother with a sleeping pad, and apparently slept all night with his headlamp on. Beware the power of the "sleep aids" legal in Colorado.

Temperature Ratings
All sleeping bags and quilts come with a temperature rating recommended by their manufacturer, i.e., 20F. However, these numbers can be confusing and even misleading. On one particularly rough night of "product testing," we slept in two bags each rated to 15F at around 15,000ft. in Nepal. It happened to snow that night, and the temperature dropped to 10-15F. Wearing all of the clothes we each had, we still both spent the night shivering mercilessly, didn't sleep for a minute, and welcomed the 3 am pre-dawn wake-up call simply to get moving again. These models did not perform well at their stated rating, so what gives?

It turns out there is only one standard for sleeping bag temperature ratings, the EN 13537 standard. To qualify for this standard test, a sleeping bag must have a hood, which rules out all but four of the bags in our test. For those that get a standard EN rating, there are two ratings — comfort and lower limit. In most cases, manufacturers publish the lower limit rating number, as was the case with the two bags we froze in, but without stating as such. It is true that we didn't freeze to death that night, so the bags did perform to their tested lower limit, but hidden on their websites was the (real) helpful information that these bag's comfort ratings were in the upper 20's, a fact we didn't know. For sleeping bags that didn't qualify for or didn't receive the EN standard test, it is not clear where the temperature rating comes from. And even those that did get a standard rating, the published numbers are most often misleading. So, take those temperature ratings with a grain of salt.

This is the amazingly light Spark I. With only 6 ounces of down filling, there are bound to be gaps. Held up to the light it is obvious that there are limits to how far one can really make this little insulation go.

While down is the insulation that traps the warmth and keeps out the cold, we found while testing these bags in frigid temperatures that little design features can make a huge difference in how warm or chilled we felt. Features like hoods, draft collars around the neck, zipper baffles, enclosed foot boxes, and mummy vs. quilt design can have a significant impact on how warm we felt inside a bag, regardless of the amount of loft. In general, traditional hooded mummy bags allowed us to burrow deeper inside our bag and stay warmer than bags without hoods. Likewise, despite their versatile and freedom granting designs, quilts inevitably permitted openings where cold air could squeeze in and were thus rarely as warm feeling as a mummy bag.

Insulated Sleeping Pads and Quilts
Most of the quilts we tested are not designed to enclose the person inside of them fully and are instead meant to wrap around one on the top and attach to a sleeping pad underneath. The idea is that if the down underneath a person is compressed, it will not provide warmth-trapping loft, so why not save the weight if it won't be used effectively? In theory, this is a smart move, but for it to work, you must take into consideration the R-value and insulating properties of your sleeping pad. Since your sleeping pad now forms a very critical part of your warmth envelope, it needs to be insulated. Check out our Sleeping Pad Review and look particularly at the R-value of the pad, higher is better. During our testing, we found that on some cold nights, even an insulated sleeping pad was not enough to keep us warm with a quilt, and so we would have appreciated the extra weight and insulation beneath us.

The Backcountry Quilt 700 kept us warm on all but the very coldest nights in Nepal, and we loved how comfortable and versatile it was.

We made a point of testing each of these bags while sleeping in temperatures very close to their stated ratings, catching two colds and spending more than a few nights shivering in the process. These experiences have taught us which bags are warm and which are not, and we rated these bags for absolute warmth, meaning the warmest got the highest score, and the coldest got the lowest score. At the top of the warmth department were the Zpacks Classic, a hoodless mummy featuring 900 fill down and box baffle construction, as well as the Patagonia 850 Down Sleeping Bag 30, , which is also a full hooded mummy that uses very thick but narrow sewn-through tube baffles. While we love quilts for their versatility and spaciousness in warmer weather, our testing revealed that in cold weather, they just don't seal off well to keep us as warm as mummy style bags.

Weight

Next to warmth, weight is the second most important consideration when choosing an ultralight sleeping bag. If you are putting together a lightweight backpacking kit, then the models represented here are all great choices for getting your base weight down near 10 pounds. For those looking to go ultralight, only the lightest of selections here should grab your attention. It is worth noting that in almost all cases, we chose the model or option that was the lightest weight, usually going with a higher temperature rating to do so. For those who want a bit more warmth and are willing to carry a few extra ounces to have it, there are usually slightly heavier, and warmer options available compared to what we tested. As the second most important metric, weight accounted for 25% of a product's final score.

When it comes to ultralight sleeping bags, most managed to shave weight with a combination of really high quality down and pared down features and design. Down provides the highest warmth-to-weight ratio of any insulation, which is why it is the only insulation used in the very lightest products. Down is rated by its fill power, and the higher the number, the more it will loft up, and thus the higher quality. In most cases, the bags tested in this review use down with a fill power of 800 or more. The fill power and quantity of down used in each competitor can be found in the specs table or on the individual product pages.

All of the ultralight sleeping bags in this review stuffed into their included stuff sacks. Notice how tiny the Spark I is on the bottom right -- no wonder we gave it a Top Pick Award! The majority of these are smaller than a similar Traditional Mummy Bag. On the top, L to R: Patagonia, Sierra Designs, Revelation 20, Superlight 15, Zpacks 20 degree. On the bottom, L to R: the two Feathered Friends, Katabatic Palisade, WM Highlite, and the Sea to Summit Ember II and Spark I.

In the case of most quilts, weight is saved by eschewing fabric or insulation on the underside of the bag. Lightweight straps or string systems help latch the sides of the quilt around the user or a sleeping pad, thereby saving the weight of a zipper as well. Quilts also forego the hood, thus avoiding the weight of more fabric and insulation. Since they retain their fully enclosed design with a hood, mummy bags are naturally heavier. They save weight by having more restrictive cuts and usually employing only a half-length zipper.

The cuben fiber roll-top waterproof stuff sack that came included with the 20 Degree was a real hit, and was, without a doubt, the best stuff sack we used during this review. Zpacks also sells these sacks on their own, and we would recommend one for all sleeping bags.

We weighed these bags individually on an independent scale to determine the weight and then assigned the scores comparatively. In the case of quilts where extra straps or buckles were required to close up the quilt or affix it to a sleeping pad, we also included that weight, but never did we add the weight of the stuff sack. The lightest bag in this review is the Sea to Summit Spark I, our Top Pick for Insane Packability. It weighs in at a remarkably low 12.7 ounces and packs into an included compression stuff sack the size of a softball. Second is the Western Mountaineering HighLite, a hooded and fully enclosed mummy style bag that manages to weigh a measly 15 ounces. Also very light is the Feathered Friends Vireo UL, a mummy style bag without a hood or zipper that features a 25F rating on the lower half and a 45F on the upper half. It is meant to be paired with a warm down jacket for ultimate comfort at a lighter weight.

The stuffed Spark I on the left in its included compression sack, smaller than a Nalgene! On the right is the Flicker 40, which is also really small inside its stuff sack, just not by comparison!

Comfort

In many ways, comfort is the quality of a sleeping bag that makes it unnoticeable. Think about it, discomfort while sleeping usually has to do with something that is bothering you. If there is no tightness constricting you, rough fabric itching you, drawcords dangling in your face, or buckles resting underneath your body, then there will be nothing causing you discomfort, and you will be comfortable. Quality sleep is one of the most important aspects of a successful backcountry trip, as you need to be able to recover after long days of difficult hiking, biking, climbing, or whatever it is you are doing. Since comfort is so important, we chose to weight it as 20% of a product's final score.

When assessing for comfort, the first thing we looked at is how well the bag fits. Our head tester is 5'11" and fairly trim, so we ordered all of the test models to suit a person 6'0" tall and standard width. By ordering them all the same size, we were able to compare the fit of each bag to the same standard. Luckily for you, all of the bags in this review come in different height and width options, making it easy to customize a bag for your particular shape. Two aspects of a sleeping bag or quilt's fit were immediately noticeable: the length and the width. Despite being made for a person 6'0", some bags were just too short, making it so the collar could not be comfortably cinched over the shoulders, or the hood could not be conveniently worn over the head.

Another issue was the width or girth. Our favorites were the roomiest, that allowed us to lie on our side or back, or squirm around between the two, without feeling like we were wrapped up in cellophane. Mummy bags are famous for being a bit claustrophobic and constrictive, but some, like the Feathered Friends Vireo UL proved to be plenty roomy. Quilts often feel more spacious and less constrictive because of their open cut, but paradoxically we found on a couple of different quilts that if it was attached to our pad, then it was too tight to lie on our side. Or, if it was a frigid night and we wanted to wrap ourselves up entirely, there just wasn't enough fabric to wrap cover all the way around us.

This Zpacks 20 Degree hoodless mummy bag was just long enough to comfortably wrap around our shoulders and cinch tight around our neck, for a pretty much perfectly comfortable fit.

Secondary to the fit of a sleeping bag is the rest of the potentially annoying comfort considerations. These include minor details such as whether the drawcord strings reside in a place where they will continuously dangle in your face, whether the liner fabric of the bag is comfortable to the touch and slippery enough for clothes to slide around unimpeded inside, and whether hoods when included, fit over the head comfortably. The presence of features that bothered us induced us to lower the comfort score a little bit.

For a mummy bag, we thought the design of the Patagonia 850 left a lot of room in the torso section, helping us avoid the feeling of claustrophobia that can be an issue with tighter mummy bags.

Ultimately, one mummy bag and one quilt proved to be the most comfortable designs in this review. The Sierra Designs Backcountry Quilt 700 was supremely satisfying because it had no zippers, buckles, or drawcords to disturb your sleep. Instead, it was designed extra wide so that it comfortably wraps all the way around you like a flour tortilla, and extra tall so you could easily duck your head inside on a cold night, or use the unique hideaway hood feature. Alternatively, the Patagonia 850 Down Sleeping Bag 30 was the most comfortable mummy bag due to its generous sizing around the torso, the deep fitting hood, and a unique foot box design that was wider, taller, and more spacious than the tighter cut of the legs above it. The little things such as a zipper baffle, drawcords on the outside of the collar, and cord lock buckles recessed within the fabric also ensured that sleep wasn't disturbed. Slightly lower scoring, but still among the top three was the Feathered Friends Vireo UL, whose vast and spacious cut in the torso is designed to accommodate the extra fill of an insulated jacket, but also left us feeling free to move about as desired.

Comparing how comfortable everyone felt in a mummy bag (orange Patagonia 850) versus a quilt (blue Revelation 20) or simply brown fur, camping on the Dolores River in the spring.

Versatility

If you want a three season sleeping bag, or are planning an epic six-month thru-hike that will span the seasons of a cool spring into hot summer and back into a cool fall, then versatility is a critical metric. Simply put, versatility is the ability of the bag to be used comfortably in the most possible (different) situations. Questions we asked ourselves when rating each bag for versatility were: is it possible to wrap oneself up like a cocoon to stay warm on the coldest nights? Likewise, is it feasible to open the bag up and ventilate to stay cool on the warmest of nights? Sleeping bags that could do both with ease were the highest scorers when it came to versatility, and sleeping bags that pigeonholed themselves into only being practical in one season or temperature range scored the lowest.

In general, we found that quilts were more versatile than ultralight mummy bags, whose half-length zipper designed with weight savings in mind often made it even harder to ventilate on warm nights. Quilts that included full-length zippers, or that were long enough and broad enough to wrap oneself up in fully, fared the best because they most easily allowed for staying warm on cold nights. Besides just being able to be used in both hot and cold seasons, we also looked at whether a bag would be serviceable in wet climates. Ultralight bags that used hydrophobic down, which is down that has been chemically treated to resist absorbing water and thereby losing its loft, and warmth-trapping properties received a bonus. We also looked at whether a bag used a DWR (durable water resistant) treatment on its outer shell to protect it from absorbing liquids such as condensation, or used a naturally water resistant fabric such as Pertex Quantum to accomplish the same thing. Lastly, we looked at how packable the sleeping bag is. The smaller it packs down, the easier it is to carry along with you, and for a few outdoor sports like bike touring or bike packing, this is a critical component of whether a piece of gear is useful or not. As an important metric, but not the most crucial metric, we weighted versatility as 15% of a product's final score.

On a chilly morning in the desert, we enjoyed the versatility of being able to wear the Flicker 40 with our feet out and the zipper done up, at least until the sun hit.

The most versatile product without a doubt was the Feathered Friends Flicker 40 UL. Made with the lightest and highest quality 950+ fill goose down, this bag is simultaneously both a quilt and a fully enclosed hoodless mummy bag, offering protection for all types of situations. On the warmest nights, it can be used as a spread out blanket, which is also ideal for two people, or as a quilt with an enclosed foot box by tightening the drawstring on the end and zipping it up partway. The full-length zipper means that on cold nights it is possible to seal it up entirely and trap the warm air in with the help of a neck baffle with dual drawcords. Simply put, no other bag so easily met the demands of all seasons. While we tested the 40F version of this bag because it was the lightest weight, it also comes in 30F and 20F versions for those who live and play in colder climates or seasons.

The Flicker 40 is one of three quilts in the review that was capable of opening up fully into a blanket on warmer nights. It was the widest or those three, big enough for two people to fit under.

Tied for second in the versatility department was the Zpacks Classic and the Sierra Designs Backcountry Quilt 700. A hoodless mummy bag that is rated to 20F features box baffle construction, and a DWR coated Pertex Nylon shell, the Zpacks Classic is ideal for cold nights. It also has a ¾ length zipper that allows one to open it up like a quilt for warmer nights. Using an opposite strategy, the Backcountry Quilt 700 is the most extensive and most expansive one person quilt with an enclosed foot box, ideal for summer comfort. Due to its size, it can wrap all the way around a person, providing an excellent cocoon in colder weather. It also uses hydrophobic DryDown to protect against condensation build up. Our favorite choice for battling wet weather was the Marmot Phase 30, which included a fantastic combination of Pertex Quantum shell and Marmot's Down Defender treatment. If you want an ultralight bag that you can utilize in all three seasons, be sure to pay attention to our versatility ratings.

One of the nice things about the Backcountry Quilt 700, and all quilts, is how easily they function as blankets to keep one warm while hanging out around camp.

Features

The features metric provides the last piece of the puzzle for understanding how well an individual ultralight sleeping bag works or doesn't work. A sleeping bag is simply a down filled sack or blanket designed to keep you warm at night, and the features are all those little components that make it work. A good analogy would be a car. A car is a motorized vehicle that allows you to go somewhere without using your human power. Its features, like the stereo, air conditioning, and drivetrain, are what allows you to be comfortable and have fun while on your way. While not as critically important as warmth or weight, features are never-the-less the pieces of a sleeping bag that you will use every night that you sleep in it, so how well they perform is very important.

The most common features found on these bags are zippers, draft collars, cinch cords around the neck, face, hood, or feet, and in the case of quilts, pad attachment systems. When assessing for features, we looked first at whether a bag's specific features functioned well or were finicky and annoying. Then we compared them to similar features on the other bags and rated them in comparison to all the others.

The two-way zipper on the Patagonia 850 is a versatile feature that allows access to the mid-section and is ideal for managing tie-in points while climbing big walls or during alpine bivies. It is also handy for pulling the draw cords for the neck and hood that live on the outside of the facial opening.

Zippers that wouldn't stay zipped or were continually getting stuck in fabric, pad straps that wouldn't stay attached or wouldn't lock in place, and drawcords that didn't have buckles or wouldn't stay tight, are examples of poorly performing features that caused us to knock the score down a bit. As something worth being aware of, but certainly not the most important overall metric, we assigned features 10% of a product's final score.

Showing how the hideaway hood feature on the Backcountry Quilt 700 works. Essentially it is a gap in the fabric that you stick your face through. A down stuffed baffle now becomes a pillow, and the rest of the quilt wraps easily around the face and upper shoulders. Despite its odd design, we found it was comfortable and worked really well to keep us warm.

Once again, our Editors' Choice Award-winning Feathered Friends Flicker 40 received the highest score for features, a perfect 10. Not only did it have a ton of features — full-length zipper with a reinforced draft tube, drawcord enclosure at the feet, dual drawcord and neck baffle at the head, optional attachment points for DIY pad straps — but they all worked well. The difference in having a full zipper versus just intermittent buttons or straps to enclose the quilt was a game-changer for trapping in heat.

The Patagonia 850 Down Sleeping Bag 30 also had a great set of features, including a two-way zipper that is ideal for accessing a tie-in point while alpine or big-wall climbing or for simple ventilation, and neck drawcords that live on the outside of the bag so the cords don't dangle in your face or wrap around your neck. We also like how the drawcord locks around the face are recessed inside the fabric for a more comfortable surface where your face rubs. Our Best Bang for the Buck Award-winning Enlightened Equipment Revelation 20 also has a great set up features, although not quite as good as the other two mentioned above.

A warm night in the Black Canyon was a great excuse for Cowboy camping in the Katabatic Gear Palisade 30. We loved the adjustability of the pad attachment straps on this pleasant evening.

Conclusion

There are hundreds, if not thousands, of sleeping bags available on the market today to choose from, ensuring it is a challenging task to find the right one. This review specializes in ultralight sleeping bags, specially designed to be as light as they can possibly be. Ultralight sleeping bags are ideal for use in the summer and depending on the climate and your sleeping system, hopefully, spring and fall as well. They are great for outdoor sports like thru-hiking, fast-packing, bike-packing, bike touring, trekking, adventure racing, alpine climbing, and any situation where weight and pack size is of critical importance to the success of the adventure. We chose these as the best and most popular 12 sleeping bags out of literally hundreds of options, and then tested them extensively in the mountains and deserts all over the world, often in quite cold temperatures, in order to provide you with the most comprehensive comparative review available today. We hope that this article, used in conjunction with the individual product reviews and our Buying Advice Article, helps you to make a purchase the suits your particular needs.